There are presently various systems for handling tarpaulins ("tarps") on load hauling vehicles such as dump trucks carrying, for example, hot asphalt, or for high sided truck or trailer bodies built specifically for cargos of such different types as sulphur, salt, grain or woodchips. Such systems usually utilize the front wall of the body for a tarp roller support while the side walls and end wall are used for support and tiedown of the sides of the tarps.
In all these cases the location of the tarp storage roller is fixed. This is usually suitable because the load is typically granular bulk material which is contained with the body walls. Also the tarps are comparatively small, since they need only cover the top of the truck body. Side protection is supplied by the walls of the body.
Flatdeck trailers are employed regularly to transport various types of freight. Such freight must usually be protected from adverse elements, such as rain or snow, to prevent damage. Since the dimensions of the freight load could be up to 8 feet high, 8 feet wide and 45 feet long, the tarp must be a minimum of 25 feet wide and 64 feet long to provide proper protection. Because of their large size, the tarp weight of a single-piece tarp would be so great that once folded the tarp would be too heavy to be handled by one man. Thus the tarp must be in two or more sections to reduce the weight of each section to a manageable size. In this way a single person can lift the tarp sections onto the top of the load in preparation for covering the load. A serious problem with tarps in several sections is that they are susceptible to water ingressing through the overlapped sections and causing damage to the freight. For example, even though two or more tarps may be overlapped so that the forward tarp overlaps the rearward tarp (which prevents water being blown under the overlap as the tractor-trailer is moving down the highway) water may nevertheless run under the overlap and onto the freight when the tractor-trailer is parked on a down-hill grade.
Storage of a tarp can also present problems. Normally the tarp would be stored folded on the trailer deck or on an under-the-deck tarp carrier, which requires further strenuous manual handling of the tarp.
The applicant is aware of the following references which are deemed to be relevant to this invention:
______________________________________ U.S. Pat. No. Inventor Issue Date ______________________________________ 2,811,321 La Barre October, 1957 2,898,147 Horner August, 1959 3,478,980 Raasch November, 1969 3,498,666 Harrawood March, 1970 3,549,199 Sibley December, 1970 4,023,857 Killion May, 1977 4,095,840 Woodard June, 1978 4,342,480 Roos, Jr. August, 1982 ______________________________________
Raasch discloses a roller for a truck cover, which can be used for loads mounted on flat truck beds or trailer beds. The roller resembles a large spool, with an enlarged circular hand grip. The tarp is wound up on the roller, and when used to cover a truck load or trailer load, is unwound such that the roller, after the tarp has been fully unrolled, rests at the rear of the truck, as shown in FIG. 2. Raasch does not disclose any capacity of the roller to rest on arms at the front of the bed, which arms can swing forwardly or laterally. Also, there is no disclosure of arms which can be extended.
La Barre teaches a truck tarpaulin reel assembly which can be mounted on the forward portion of an open top truck body. The reel assembly includes a pair of support brackets mounted on the sides of the truck body and support arms which are pivotally carried by the brackets. The reel can be position either in a storage position, or in a tarpaulin tensioning position which is forward and below the forward upper edge of the truck body. There is no teaching in La Barre of moving the reel forward or rearwardly in order to accommodate different load positions on the truck body.
Horner discloses a truck bed cover which consists of a reel and reel mounting means for detachably mounting the reel on a truck body. The reel has a telescoping capability which enables it to be adapted to be used on trucks of various length. There is also a capability to adjust the cover and guides to suit trucks of various widths. There is no disclosure of swingable or extendable arms, or any capacity to move the cover means forward or rearward on the truck.
Harrawood discloses a roll up load cover apparatus for dump truck bodies. A swingable arm is disclosed.
Sibley discloses a cover and reel arrangement for dump trucks, the assembly pivoting about a mid point of the truck body.
Killion discloses a tarpaulin-reel assembly for use in covering the open top of a truck body. Instead of a long swing arm, Killion utilizes an arm which can be moved along a track mounted on the side of the truck body.
Woodard also discloses a retractable cover for use on an open top truck body. A swingable arm pivots about a mid point of the truck body. The swingable arm, as illustrated in FIGS. 1 and 2, can swing from a forward position (FIG. 2) to a rearward position where the tarpaulin is extended over the top of the truck body. Woodard does not disclose any capacity to move the swing arm forwardly or rearwardly on the truck body.
Lastly, Ross, Jr. discloses a mechanized enclosure system for flat bed trailers. Rather than roll up the tarpaulin or cover, Ross, Jr. shows a collapsible bellows type arrangement whereby in a compacted form, the tarp or cover can be grouped at the front end of the flat bed trailer, while in a fully extended position, the tarp or cover extends along both sides and over the top of the flat bed trailer.
Finally, the inventor is also aware of U.S. Pat. No. 3,768,540, McSwain, which speaks about a telescoping arm for a tarpaulin spool.